Synchronous motor drive systems composed of a synchronous motor and a drive device are incorporated in various devices, such as compressors, electric vehicles, hybrid vehicles, and fuel-cell vehicles.
FIG. 18 is a plan view of a synchronous motor described in Patent Literature 1.
The synchronous motor is composed of a rotor 52 and a stator 53. The rotor 52 includes a rotor core 54 and four permanent magnets 55. The stator 53 includes an annular stator yoke 57 and six stator teeth 58 which are arranged circumferentially on the stator yoke 57 at spaced intervals. The stator teeth 58 have outer coils Uo, Vo, and Wo and inner coils Ui, Vi, and Wi. Each coil is wound around in concentrated winding and disposed at an electrical angle of π radians with respect to a corresponding outer or inner coil. As the drive device, a three-phase inverter is disclosed. The coils Uo and Ui commonly receive U-phase electric current, the coils Vo and Vi commonly receive V-phase electric current, and the coils Wo and Wi commonly receive W-phase electric current.